1. Field of the Invention
This invention relates to an apparatus for incorporating or assembling components and simultaneously filling liquid for the assembly of a liquid-sealed vibration-proof mount, which is principally used for supporting an automotive engine, etc. in a vibration-proof manner.
2. Description of Related Art
As a mount for supporting and bearing an automotive engine or the like so as not to transmit its vibrations to the vehicle body, there is known a liquid-sealed vibration-proof mount as exemplified in FIG. 12, which comprises a main body fitting 2 of a circular form, a rubber elastomer 3 as a vibration-isolating base and a diaphragm 4 thereby constituting part of a room wall and an interior of a main body filled with liquid, a partition 5 partitioning the interior into upper and lower liquid chambers 6a, 6b so that both liquid chambers may communicate with each other through an orifice 7 in the partition 5, whereby vibrations are attenuated and absorbed owing to the liquid fluidization resistance by the orifice 7 and the vibration-isolating effect of the rubber elastomer 3.
Such a liquid-sealed type of vibration-proof mount is assembled in such a procedure that main components body 1 having an interior space for filling liquid is beforehand fabricated by vulcanization-bonding the rubber elastomer 3 to an opening end side of the main body fitting 2 and vulcanization-bonding an attachment fitting 8 to the rubber elastomer 3; companion components to the main components body 1, i.e. the partition 5, the diaphragm 4 and so on are incorporated into the main components body 1 and concurrently, the interior is filled with liquid in a sealing manner.
For the work of incorporating or assembling the components into the main body 1 and of sealing liquid in the assembly of the above-mentioned vibration-proof mount, a rather large liquid tank has been hitherto used. This components incorporating work was conducted in liquid by setting sequential steps comprising: a step of setting and holding the main components body within the liquid in this liquid tank, a step of incorporating the components including the partition, diaphragm, etc. into the main components body, a caulking step for locking the components thus incorporated and assembled, and a step of removing the mount thus assembled out of the liquid tank.
With the conventional system of simultaneously incorporating components and sealing liquid for the vibration-proof mount, large-scale conveying means as well as a large-sized liquid tank were needed and accordingly, an installation space for them becomes large and besides, the change work in setting height, treatments against troubles and maintenance control were awkward and troublesome. Moreover, extraneous matters such as molding sand, rubber remnant, etc. tended to creep in the liquid tank, which were likely to be responsible for entrainment of bubbles, etc. causing a poor assembling. Further problem was that cleaning work for an outer peripheral portion of the mount product after assembly was troublesome.
To overcome the prior art problems described above, therefore, the present inventors have formerly proposed a system for incorporating components and sealing liquid using a relatively small liquid tank, which is disclosed in JP Patent Publication 11(1999)-230235 A.
The formerly proposed system comprises, while holding a main components body faced upwardly in a nearly upright state, depressing a liquid tank that is positioned upwardly of the main components body to be capable of ascending or descending and possesses an aperture at a part of its bottom; fitting the aperture to an outer periphery of the main components body to install the tank to the main components body so as to maintain a sealing state; supplying liquid onto the bottom of the liquid tank where the aperture is disposed, thus flowing the liquid into the interior space of the main components body through its opening and storing a required amount of liquid on the bottom; soaking components, i.e. a partition, a diaphragm and so on in the liquid, as it is stored, and fitting them, under deaeration, into the interior and the opening of the main components body by actuating a components incorporating mechanism composed of a multi-spindle articulated robot, etc. thereby incorporating them and filling liquid; and thereafter discharging the liquid stored in the liquid tank out of the bottom and removing the liquid tank from the main components body.
Here, when incorporating components in the condition that the liquid is supplied and stored on the bottom of the liquid tank, it is required to ensure that a liquid level height of the stored liquid be more than a definite value, from the viewpoints of conducting deaeration operation of the components and preventing entrainment of bubbles. That is, the less the liquid amount and the lower the liquid level height, the more difficult is the deaeration operation and the more easily are the bubbles entrained. As a consequence, it is necessary to replenish the liquid appropriately, depending on the decrease or decrement in liquid amount every liquid sealing work.
To that end, it was contrived to provide liquid replenishing means for replenishing liquid to the liquid tank such as a pump together with a liquid level detector tube for detecting the liquid level height, by means of which the fact that the liquid level height has reached a definite level is detected as a detection signal, on the basis of which the actuation of the components incorporating mechanism may be controlled. On the other hand, in cases where the liquid level height does not reach a definite level, the liquid replenishing means is actuated on the basis of the detection signal so that liquid may be replenished.
In cases where the liquid is supplied onto the bottom of the liquid tank every work for incorporating components and sealing liquid as mentioned above, however, the problems were encountered that the liquid level was liable to fluctuate up and down owing to the fluidization action of the liquid when supplied and impacts upon incorporation of components by means of a hand of the components incorporating mechanism. Further also inside the liquid level detector tube, the liquid will pulsate up and down accompanied thereby. Stated another way, due to the aforementioned pulsation, the liquid level detector tube will detect that the liquid level has reached a definite level earlier than the actual rise in liquid level or will detect repeatedly the situations where the liquid level height is above and below the definite level.
As a result, the actuation of the components incorporating mechanism comes to start earlier and the deaeration operation upon incorporation of components will be insufficient, which leads to a danger of entrainment of bubbles. Otherwise the components incorporating mechanism will cause an error operation or the operation of it will be frequently suspended, which is responsible for failure of the mechanism and detracts from the durability.
The present invention has been made to solve the foregoing problems of the components incorporating and liquid sealing apparatus mentioned above taking advantage of the ascending and descending of the liquid tank and the liquid supply and discharge actions. Accordingly, the invention is aimed at enabling the liquid level height upon supplying of liquid to be detected accurately thereby ensuring the control of the apparatus based on the detecting signal and at enabling the components incorporating and liquid sealing work to be carried out with high efficiency.
The invention is concerned, in a broad sense, with an apparatus for incorporating components and sealing liquid for the assembly of a liquid-sealed vibration-proof mount, which comprises a setting and holding section for a main components body, wherein the main components body for the vibration-proof mount having an interior space and an opening at one end side thereof is supported and secured in place in a substantially upright state with the opening faced upwards; a liquid tank positioned upwardly of the main body setting and holding section so as to be capable of ascending and descending, the liquid tank having at its bottom an aperture which can be fitted hermetically to an outer peripheral portion of the main components body and capable of storing liquid on the bottom in the condition that the liquid tank is assembled to the main components body by fitting of the aperture to it; liquid tank elevating or depressing means supporting the liquid tank located upwardly of the main body setting and holding section and lowering the liquid tank toward the main components body so as to fit the aperture to the main components body and raising the liquid tank so as to release from the main components body; liquid supply and discharge means for supplying or discharging the liquid onto or from the bottom of the liquid tank having the aperture in conformity with the installing action or removal action of the liquid tank in or from the main components body; liquid replenishing means for replenishing liquid whenever appropriate into the liquid tank; and a components incorporating mechanism for holding and shifting components inclusive of a partition and a diaphragm to the main components body in the liquid as stored on the bottom of the liquid tank, thereby conducting incorporating operation. In the aforementioned apparatus, the invention is characterized in that a liquid level detector tube for detecting a liquid level height upon supplying of liquid onto the bottom is disposed to be coupled to the liquid tank and further provided with valve means suppressing pulsation of the liquid surface; and the liquid level detector tube is adapted and constructed so that the actuation of the aforesaid components incorporating mechanism may be controlled on the basis of detecting signals of the liquid level height by means of the liquid level detector tube.
According to this apparatus for incorporating components and sealing liquid of this invention, the main components body of the anti-vibratory mount is held in a substantially upright state with its opening faced upwardly by means of the main body setting means, whereas the liquid tank positioned upwardly of the setting means is depressed and mounted to the main components body by fitting the aperture at the bottom to it in a sealing condition. When liquid is supplied onto the bottom of the liquid tank in this manner, part of the liquid is flowed through the opening of the main components body into the interior space, where the liquid is filled, concurrently with which a predetermined amount of liquid is stored on the bottom.
At that time, the liquid level height on the bottom of the liquid tank is detected with the aid of the liquid level detector tube. When the liquid level height reaches above a definite level, the liquid level detector tube detects it to transmit a detecting signal, on the basis of which the aforesaid components incorporating mechanism is actuated. In particular, seeing that the liquid level detector tube is equipped with valve means for suppressing the pulsation of the liquid face inside it, even if the liquid inside the liquid tank fluctuates in a manner rising and falling to a great degree owing to the supply action of the liquid onto the bottom, the valve means at the liquid level detector tube serves to suppress the exhaustion of air. As a result, the liquid face moves slowly to suppress the pulsation and the liquid level height can therefore be detected correctly.
Further on the basis of the detecting signal when detecting a liquid level height of more than the definite level, the components incorporating mechanism is actuated so that components including a partition, a diaphragm, etc. are held, in order, and subjected to deaeration operation, for example by soaking in the stored liquid in a tilted posture and thereafter fitted, in a horizontal posture, into the main components body, which is received in the aperture of the bottom of the liquid tank, through its opening to incorporate them into it and concurrently, to seal the liquid in it. Should the liquid within the liquid tank fluctuate upon this incorporating operation, the liquid face within the liquid level detector tube is free from pulsating excessively, so that any error operation due to pulsation does not occur. Thereafter the components incorporating mechanism is restored to the initial condition and the liquid is discharged from the bottom of the liquid tank, and subsequently, the liquid tank is elevated and disengaged from the main components body. After the holding action by the main body setting and holding section is released, the vibration-proof mount thus assembled is conveyed from the main body setting and holding section to subsequent steps, e.g. crimping step and the assembly is completed.
According to the apparatus for incorporating components and sealing liquid of this invention as described above, the incorporating operation by means of the components incorporating mechanism is conducted so that while the main components body is being secured and held in place without shifting, a relatively small liquid tank is mounted by descending action to and removed by ascending action from the main components body and furthermore, liquid is supplied to or discharged from the bottom of the tank. Hence the incorporating operation of components is facilitated without soaking the entirety of the main components body in the liquid and the overall apparatus can thus be compactified.
In particular, on account of the fact that the liquid level height on the bottom of the liquid tank upon supplying of liquid is adapted to be detected correctly by suppressing the pulsation, the components incorporating work can be efficiently conducted without the occurrence of the problems that the components incorporating mechanism is actuated too early or its operation is suspended, and entrainment of bubbles can be avoided. Furthermore, the occurrence of failure of the apparatus is prevented and its durability is improved.
The aforementioned liquid level detector tube has vertically a detecting piping coupled to a lower part of the tank so that liquid can flow in it. The detecting piping is provided at least partly with a transparent tube part and a level sensor for detecting the liquid level height of inflow liquid at the transparent tube part so that detecting signals of the level sensor may be transmitted to an apparatus control section. By that provision, the detection of liquid level by means of the level sensor can be performed precisely. The adjustment of position of the level sensor facilitates setting an optimal liquid level height in conformity with the configuration of a vibration-proof mount and the shapes of components to be assembled.
The valve means for suppressing pulsation is provided at an exhaust part of the liquid level detector tube and includes an exhaust throttle valve limiting the exhaust volume upon inflow of liquid. Thereby with the rise of the liquid level on the bottom of the tank, for instance, when liquid flows in the detecting tube and the air within the detecting tube is expelled into the atmospheric air, this exhausting action is suppressed by the exhaust throttle valve, as a result of which the inflow speed of the liquid into the detecting piping is controlled to restrain the pulsation of liquid, thereby permitting the liquid level height to be detected correctly.